Process of treating pulp.



G. MOORE.

PROCESS OF TREATING PULP.

APPLICATION FILED 1mg. 23. 1915.

Patented Dec. 12, 1918.

2 SHEETS-SHEET 1.

G. MOORE.

PROCESS OF TREATING PULP.

APPLICATION FILED JAN-23. 915.

Patentfid Dec. 12, 1916.

2 SHEETS-SHEET 2- lvwemtoz .llmprovements in Processes of Treating as.4.. .lh..-

specification of Patent.

Patented Dee. it, llttiltt.

application .tanuary tit, wit. teriat Ito. aura .Zlb ail whom it mayconcern Be it lmown that ii, Gannon r loonn, a cititen of the UnitedStates, residing at Joplin,

the county of Jasper and State of Missouri, have invented certain newand useful Pulp; and it do hereby declare the following lift to he afull, clear,.and exact description of the invention, such as will enableothers slfilled in the art to which it appertains to make and use thesame. I

This invention relates more particularly to the art of recovering paperpulp and especially wood pulp, from waste water from paper mamngmachines.

It is well own that-large quantities of valuable paper pulp are fiowedofi' from paper making machines, the lost pulp bemg suspended in thewater in such finely divided state as to render dificult its recovery'ina sufilciently rapid manner as to render such recovery profitable, andit is also known that the paper pulp possesses characteristicdifrerences from other forms of pulp, one of i which is its lack ofstability when deposited in the form of a layer or cake, which lackrenders it difiicult to move a support susa vertical layer or deposit ofsuch pulp, so that proposed methods of coating a strainer or filtersurface with such pulp and then moving the surface toa oint of deposithave been fraught with dilticulties, and it is one of the objects of theresent invention to overcome all of these ifficulties and to render therecovery of such waste pulp rapid and profitable.

in carrying out the present improved process, it is preferable to employcertain apparatus, and a detail understanding of the process may be hadmost readily by reference to the structure and operation of suchapparatus, so that l have to this end shown an embodiment of suchapparatus in the accompanying drawing, in which,

Figure l is a view partly in elevation. Fig. 2 is a similar view takenat right angles to the plane of observa tion of Fig.1. Fig.3 isa topplan view thereof with the conveyor omitted. Fig. t is an enlargeddetail fragmentary view of a portion of the rotary screen. Figs. 5 and.6 are front elevations respectivel of two plates of the distributingvalve. ig. 7 is a fragmentary elevation of a part of one of the foraousplates of one of the strainer leaves or cells.

partly in section and Fig; 8 is a vertical section taken on the plane in'cated by line it, 8, of Fig. '2. 7

Referring to the drawing by numerals, l indicatesa tank into which thewaste water from paper making machines is delivered through a pipe 2,controlled by a valve 3, the pie 2 leading from a source of supply at asucient elevation for filling tank l when the valve 3. is opened.Arranged within the tank l. are filter leaves or cells t, t, each madeup of a pair of spaced foraminous sheets or plates 0 metal t, or otherappropriate reticulated sheets may be employed as, for instance, a finemeshscreen. The plates t are closed in around their edges and connectedat various points by solder 4:, so that water entering the space betweenthe plates can approach only throuph the openings in the plates.Extending a ong the lower edge of each cell t is a passage-way 5, whichis provided by the" merely an enlargementspacing of the lower portlon ofthe plates so as to accommodate the flow of water along the lower edgeof. the cell to the discharge pipe 6, a discharge pipe 6 being providedfor each cell 4: and each ipe extending with the water-tight joint'hrough a tapering plug 7, designed to fit a corresponding aperture inthe bottom of tank 1. Each pipe 6' size suficient to allow the passageof a section of the joint 6' so that when the joint is disconnected theparticular leaf t may be withdrawn from the tank, the upper section ofthe joint passing through the aperture which is normally closed by therespective plug 7. The several cells 4 may be retained in position inany of various ways, as, for instance, by a cross plate or bar fixed tothe upper portion of the side walls of tanlr l and extending across andfixed to the upper edge of the several cells 4-.

A reverse current supply pipe 9 communicates with pipe 9 and is valvedas at 9". The source of the reverse current is not indicated but may beeither water or air under sufficient pressure. The lower end of thedischarge pipe 9 extends into a water seal ll, and the said dischargepipe is provided with a controlling valve 12. The water from the tank orwater seal 11 is decanted through a launder 13 or otherwiseappropriately disposed of.

Arranged at one side of tank- 1 is a tank '14 in which is journaled arotary screen 15.

of a shaft 16- journaled on the walls of tank 14 at the up- The screenconsists merely per edge thereof and having radial spokes 17, 17carrying a peripheral screen portion 18, divided into sections bypartitions 19. The spokes 17 at one end of the drum or rotary screen areall tubular and are arranged with one of the tubular spokes incommunication with each peripheral pompartment, the several tubularspokes being turned as at 17 at the point of engagement with shaft 6,and'extended into an appropriate aperture 20 in the disk 21 of a ressurecontrolling valve consisting of sai disk and a cooperating disk 22. Thedisk 22 is provided with segmental grooves 23 and 24, and an opening orvery short. groove 25. The

' groove 23 communicates with a pipe 23' which connects with a suctionpump or gravity column of water,-while the groove 24 communicates with apipe 24, connected with a suction pump, and the aperture orgroove 25communicates with a ipe 25' connected with a source of air supp y fordelivering a blast of air traveling in converse direction to the travelof current in pipes 23' and 24. The pumps mentioned and the source ofcompressed air are not illustrated since they may be of any well knownform. It should be clear that as the rotary screen 15 revolves, beingdriven by belting 26, from any source of power not illustrated, theseveral openings 20 will be caused to; successively register with thegrooves 23, 24 and 25 so that while the sections of screen are wit inthe fluid in tank 14, they are subjected to suction through pipe 23, andwhen the particular section of screen passes above the liquid level intank 14,-the respective aperture 20 is brought into register with groove24, whereby water is drawn from thecakes and if air is drawn in, it doesnot reducesuction of main line acting on submerged sections. When asection approaches scraper 27, the respective aperture 20 comes intoregister with groove or aperture 25 and an instantaneous blast of air isdirected outward through the screen section so thatthe coating of pulpsolids will be lifted by the air blast and directed to the upper surfaceof the scraper 28, from which it falls to a chute 29, and is therebydirected to any appropriate point of disposal.

An endless conveyer 30 is arranged above tank 1 with its lo'wer l'approvided with pendant plates or scrapers 31, disposed to engage thethickened pulp solids floating on the surface of the liquid in tank 1and move the same over a guide-way 14' between tank 1 and tank 14.Instead of the rotary employed, such as an endless screen traveling overhoppers to which suction is a plied.

In practism the process by emp oying the'apparatus ust described, thetank 1 being filled with the waste water, the water is drawn off throughthe several cells 4, and discharged through the pipe 9. The flow ofwater into each of the cells is caused by the difference in pressurebetween the exterior and the interior of the cell, which difference inpressure may be maintained in various ways, as will be apparent, thatshown being principally incident to the difference in level between theintake points of the cells and the discharge point for water seal 11.This discharging of water is continued and the suppl is kept u throughpipe 2 for maintaining the liqui level in tank 1 above the cells 4 untilcakes of pulp have formed on the faces of the several cells. Thereupon,the supply is out 01f by closing valve 3 while the discharge of waterthrough pipe 9 continues until the cakes of pulp on the sides of thefilter cells are exposed to the air, the continued discharge of thewater through pipe 9 servin to suck air in through the several cakes andthus aeratin the particles of paper pulp, usually woo pulp. The valve 12is then closed, and the supply to pipe 2 restored by the opening ofvalve 3. After the cells have been submerged, thevalve 3 is againpreferably closed" and the" valve 9" is opened, admitting a reverse orcounter current into the several cells acting outward and throwing oi?the pulp collected thereon. The particles of pul having been aerated andretaining air ubbles, are rendered buoyant, andimmediatel .u on" theirdischarge from the filter cel s, t ey rise to the conveyer 13, whichcollects and drags them over the partition 14' and discharges them intotank 14. As soon as the collected pul discharged from the filter cellshas arrive at the surface of the water in tank 1, the

valve 9 is closed, and valves 3 and 12 are opened, and that portion ofthe process involved in the collection of solids on the filter cellsrepeated.

The conveyer 30 continues to collect the floating pulp and to dischargethe same into tank 14, where the rotary screen 15 is revolving andacting to remove a large portion of the moisture remaining in the pulp.As the screen 15 revolves, a cake of pulp is built on each submergedsection by the difierence in pressure between the exterior and interiorof the section, the difference being maintained preferably by suctionapplied to the respective section through the valve arrangement abovedescribed, which operates after the manner set forth in detail in myPatent, No. 746,552,

dated December 8, 1903, the present valve screen, any other dewateringdevice may be managers structure, however, having two suction pumpconnections, one for building the cakes and one for dewatering thecakes. 'Ihe built-up cakes are prevented from falling 0d by the suctionuntil they reach the point of the scraper, where they are removed by thescraper aided by a blast of air discharging outwardly from within therespective section of the screen. In working some pulp, it may be foundsufficient to omit the air blast and depend merely upon the scraper forremoving the cakes.

What I claim is:

1. In a process of recovering paper pulp from water bearing suspendedpulp solids,

submerging a filter cell in such water, passing water. through the cellfor depositing solids of pulp thereon while maintaining the cellsubmerged until a coat of solids is formed on the cell, aerating thesolids forming such coating, and discharging the solids coating from thecell while submerged.

2. In a process of recovering paper pulp from water bearing suspendedpulp solids, passing Water of such Waste water through a filter cellWhile maintaining the cell submerged in Waste water for depositing acake of pulp solids on the filter cell, exposing the coated cell to theatmosphere, drawing air through the coating into the cell, re-

submerging the cell, and discharging the coating while thus submerged.

3. In a process of recovering paper pulp from water bearing suspendedpulp solids, thickening the pulp in a body of such water, delivering thethickened pulp to a body of such pulp, forming a cake of solids of suchbody of pulp on a screen by difference in pressure at one side of thescreen from that at the other, moving, the thus formed cake from thebodyof pulp into the atmosphere, maintaining the cake in position on thescreen by a like difference in pressure, dewatering the cake, andreversing the difference in pressure for discharging the cake from thescreen beyond the body of thickened pulp.

4. In a process of recovering paper pulp from waste Water, thickeningpulp in a body of water, aerating the thickened pulp, and

causing the pulp to float on a body of water.

5. Thickening paper pulp in water, and floating the pulp by means ofbubbles.

In testimony whereof I aflix my signature in presence of two Witnesses.

GEORGE MOORE. Witnesses:

' Ii. DUNcANsON, M. 'I. SHEA.

